New Manufacturing Process Creates Super-Small Channels to…

The process has potential to improve medical and electronics devices, researchers say

WEST LAFAYETTE, Ind.—A new manufacturing process developed by Purdue University researchers may improve the water repellency for some common products, ranging from medical equipment and sensors to vehicle engines and windshields.

This image shows the creation of a super-hydrophobic surface on a metal surface by an ultrafast laser, which is transferred to PMDS via transfer molding and assembled into a microfluidic device. (Image courtesy of Purdue Research Foundation/Purdue Office of Technology Commercialization)

The Purdue team, led by Yung Shin, the Donald A. and Nancy G. Roach Professor of Advanced Manufacturing in the Purdue School of Mechanical Engineering, developed a new method to create super-hydrophobic micro channels on polymers. This technology provides a quick and inexpensive fabrication technique to create microfluidic devices having channels with controllable flow rates, without the use of chemical treatments or complex flow-control devices.

“These are basically small channels that are made in such a way that water cannot stick to the surface or give little resistance in the flow,” Shin said in a press release. “You can then send water or other liquids through and create smaller cooling channels and microfluidic devices.”

This image shows a water drop on a created super-hydrophobic surface, showing a very high contact angle. Purdue University researchers developed a new manufacturing process to improve the water repellency for some common products. (Image courtesy of Purdue Research Foundation/Purdue Office of Technology Commercialization)

Shin’s team uses a two-step process to create the super-hydrophobic surfaces. First, they create patterns or features on a metal surface with an ultra-fast laser. Then, in a process called transfer molding, the researchers create that same pattern on the polymer.

“Our process is unique because it allows for the creation of these surface patterns or features on the inside of the polymer, and not just the outside,” Shin said. “We are essentially using these features to control flow rates without the need for expensive chemical treatments and coatings that can be washed away or wear off.”

Shin said the technology has many potential applications, including medical equipment and sensors that use circulating fluid to detect abnormalities or unhealthy conditions in a patient. It could also be used for micro cooling systems for electronics, microfluidic devices, microelectro-mechanical systems (MEMS), self-cleaning surfaces, and micro hydraulics systems in airplanes and automobiles. The technology could help create windshields that are better able to repel water and require less wiping.

The technology may also be used, according to Shin, in heat exchangers by removing condensed water drops, improving the heat transfer efficiency. Another possible application is for electronic devices.

“Our technology can help with the continued miniaturization of electronic devices, such as phones and computers,” Shin said. “Our method of creating these super-hydrophobic micro channels allows for smaller devices that perform at the same efficiency as much larger ones.”

The Purdue Office of Technology Commercialization helped secure a patent for the technology, which is available for licensing.